The A/C compressor won’t kick on.

When I turn ON the air conditioner, I get the fan, but the compressor clutch does not kick on. The fuse is good, as the other items on that same circuit all function properly. I do not get power at the compressor. I did run a hot wire from the compressor to the battery (+) and the compressor clutch kicks on like it is supposed to. So, I know the compressor works, and I know I am not getting power to the compressor when it is all plugged in normally. All of the other heat and vent functions, and the fan, all work as they are supposed to.

This is NOT Auto-Temp III!!!

I do not have a '78 FSM, so I'm a little bit stumped here.
Anyone have an idea what's up? It worked just fine last Summer, and would freeze you out. It was properly converted to R134 in 2006 by the PO, with a new drier & condensor.
Author: patrick66